Health Hotline Magazine | September 2025

NUTRITION

By Geoff Brokx and Katherine MacNair

Low Choline Intake Reduces Strength Gains in Resistance Exercise

A 2023 study published in the journal Nutrients found that low choline intake reduces strength gains in older adults participating in resistance exercise. The study included 37 generally healthy males and females aged 50 to 69. Participants were divided into three groups to receive a supplement providing 0.7, 2.8, or 7.5 mg of choline per kilogram of body weight daily during a 12-week resistance training program. These amounts represented approximately 50%, 70%, and 120% of the Adequate Intake (AI) for choline. All participants followed a similar healthy diet with consistent calorie, carbohydrate, fat, and protein intake, and strength improvements were tracked throughout the program. The researchers found that participants in the low choline group had significantly lower gains in strength compared to those in the medium- and high-choline groups. Several mechanisms may explain these findings. First, choline is a precursor to the neurotransmitter acetylcholine, which transmits signals from motor neurons to skeletal muscle to regulate contraction. Without sufficient acetylcholine, muscle

Vitamin D May Be the Key to Healthy Cellu ar Aging This research underscores choline’s critical role in musculoskeletal health and extends its benefits beyond its well-known support for liver and brain function. With estimates suggesting that roughly nine out of 10 people fail to meet the AI for choline, this study offers yet another reason to prioritize this essential nutrient. contractions may be compromised. Second, choline supports the production of betaine, which is required to make SAMe—the body’s universal methyl donor. Methylation is essential for muscle repair, protein synthesis, and recovery, making choline particularly important during resistance training. Lastly, choline is a precursor to phosphatidylcholine, a key fat used to build cell membranes. Inadequate choline intake may reduce the structural integrity of muscle cells under the mechanical stress of resistance exercise.

The wide-ranging health benefits of having optimal levels of vitamin D are well known: bone health, immune function, and heart health, to name a few. But can the sunshine vitamin also help slow down the clock of biological aging? A 2025 study published in the American Journal of Clinical Nutrition looked at the effect of long-term vitamin D supplementation on the aging process at the cellular level. Older adult participants took either 2,000 IU of vitamin D3 daily or a placebo for four years. To assess the aging process, researchers measured the telomere length of the participants’ white blood cells at baseline, two years, and four years. Telomeres are protective caps on the ends of chromosomes, which are long strands of genetic material—like the plastic tips on the ends of shoelaces. They help keep the DNA in the chromosomes from getting damaged or unraveling. Every time a cell divides, the telomeres get a tiny bit shorter. Over time, they can become too short to safeguard the DNA effectively. When this happens, cells may stop dividing or function less efficiently, contributing to signs of aging and an increased risk of chronic conditions such as cancer and autoimmune disorders.

The researchers in the study found that vitamin D supplementation reduced the shortening of the participants’ telomeres by 140 base pairs over four years, compared to placebo. Based on previous studies, the preservation of 140 base pairs is roughly equivalent to a three-year decrease in aging. In other words, the group taking vitamin D kept their telomeres younger for about three years longer than those that did not. Scientists are still working to discover what the reasons for this could be. One hypothesis is that vitamin D helps increase the activity of an enzyme that lengthens telomeres. Another explanation is that vitamin D influences multiple cellular signaling pathways involved in reducing inflammation and promoting repair, both of which may help protect telomeres. So the next time you’re considering anti-aging creams and lotions, don’t forget to nourish your cells from within with vitamin D!

For references, please visit: naturalgrocers.com/issue-98

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